-
Notifications
You must be signed in to change notification settings - Fork 4
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Kai Clemens Liebich (AE/ESC2.1)
committed
Oct 21, 2019
1 parent
8369c23
commit 86bef65
Showing
112 changed files
with
13,071 additions
and
0 deletions.
There are no files selected for viewing
Large diffs are not rendered by default.
Oops, something went wrong.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,46 @@ | ||
| Arduino Task Scheduler | ||
| ---------------------- | ||
|
|
||
| This library implements a simple, preemptive task scheduler that is executed in parallel to the 1ms timer interrupt | ||
| used for the Arduino millis() function. It allows to define cyclic tasks or tasks that should be executed in the future | ||
| in parallel to the normal program execution inside the main loop. | ||
|
|
||
| The task scheduler is executed every 1ms. A possibly running task is interrupted by this and only resumed after all succeeding tasks have finished. This means | ||
| that always the task started last has the highest priority. This effect needs to be kept in mind when programming a software using this library. | ||
|
|
||
| Notes: | ||
| - Deadlocks can appear when one task waits for another taks which was started before. | ||
| - Timing critical tasks may not execute properly when they are interrupted for too long by other tasks. Thus it is recommended to keep task execution as short as possible. | ||
| - The Arduino MEGA leaves the interrupts state shortly after starting the task scheduler which makes the scheduler reentrant and allows any other interrupt (timer, UART, etc.) to be triggered. | ||
| - The Arduino DUE enables other interrupts by using the lowest possible priority (15) for the task scheduler interrupt. | ||
|
|
||
| Warning: The Arduino Due does not support reeantrant interrupts due to HW limitations. This means that unlike the Arduino MEGA the DUE is not able to execute | ||
| fast 1ms tasks several times before finishing a slower tasks with for example a 10ms timebase. This problem will be especially visible if the sum of the | ||
| execution time of all tasks is greater than the execution period of the fastest task. | ||
|
|
||
| Supported Boards: | ||
| - all boards using the Atmel ATMega328 controller, e.g. Arduino Uno and Nano | ||
| - all boards using the Atmel ATMega2560 controller, e.g. Arduino Mega | ||
| - all boards using the Atmel SAM3X8E controller, e.g. Arduino Due | ||
|
|
||
| Consumed interrupt: | ||
| - Atmel ATMega328 & ATMega2560: Scheduler uses TIMER0_COMPA interrupt. This maintains millis() and analogWrite() functionality on T0 pins. However, | ||
| frequent changes of the duty cycle using analogWrite() lead to a jitter in scheduler timing. | ||
| - Atmel SAM3X8E: Scheduler uses TC3 interrupt. | ||
|
|
||
| CPU runtime: | ||
| - Atmel ATMega328 & ATMega2560: | ||
| - 5μs without pending tasks | ||
| - 12μs + task duration when tasks are executed | ||
| - Atmel SAM3X8E: | ||
| - tbdμs without pending tasks | ||
| - tbdμs + task duration when tasks are executed | ||
|
|
||
| Have fun! | ||
|
|
||
| ==================================== | ||
|
|
||
| # Revision History | ||
|
|
||
| 1.0 (2019-10-12): | ||
| - initial release |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,169 @@ | ||
| <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> | ||
| <html xmlns="http://www.w3.org/1999/xhtml"> | ||
| <head> | ||
| <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> | ||
| <meta http-equiv="X-UA-Compatible" content="IE=9"/> | ||
| <meta name="generator" content="Doxygen 1.8.9.1"/> | ||
| <title>Task scheduler library: README.md Source File</title> | ||
| <link href="tabs.css" rel="stylesheet" type="text/css"/> | ||
| <script type="text/javascript" src="jquery.js"></script> | ||
| <script type="text/javascript" src="dynsections.js"></script> | ||
| <link href="navtree.css" rel="stylesheet" type="text/css"/> | ||
| <script type="text/javascript" src="resize.js"></script> | ||
| <script type="text/javascript" src="navtreedata.js"></script> | ||
| <script type="text/javascript" src="navtree.js"></script> | ||
| <script type="text/javascript"> | ||
| $(document).ready(initResizable); | ||
| $(window).load(resizeHeight); | ||
| </script> | ||
| <link href="search/search.css" rel="stylesheet" type="text/css"/> | ||
| <script type="text/javascript" src="search/searchdata.js"></script> | ||
| <script type="text/javascript" src="search/search.js"></script> | ||
| <script type="text/javascript"> | ||
| $(document).ready(function() { init_search(); }); | ||
| </script> | ||
| <link href="doxygen.css" rel="stylesheet" type="text/css" /> | ||
| </head> | ||
| <body> | ||
| <div id="top"><!-- do not remove this div, it is closed by doxygen! --> | ||
| <div id="titlearea"> | ||
| <table cellspacing="0" cellpadding="0"> | ||
| <tbody> | ||
| <tr style="height: 56px;"> | ||
| <td id="projectlogo"><img alt="Logo" src="scheduler.png"/></td> | ||
| <td style="padding-left: 0.5em;"> | ||
| <div id="projectname">Task scheduler library | ||
|  <span id="projectnumber">1.0</span> | ||
| </div> | ||
| <div id="projectbrief">Arduino library for simply executing tasks in parallel</div> | ||
| </td> | ||
| </tr> | ||
| </tbody> | ||
| </table> | ||
| </div> | ||
| <!-- end header part --> | ||
| <!-- Generated by Doxygen 1.8.9.1 --> | ||
| <script type="text/javascript"> | ||
| var searchBox = new SearchBox("searchBox", "search",false,'Search'); | ||
| </script> | ||
| <div id="navrow1" class="tabs"> | ||
| <ul class="tablist"> | ||
| <li><a href="index.html"><span>Main Page</span></a></li> | ||
| <li class="current"><a href="files.html"><span>Files</span></a></li> | ||
| <li> | ||
| <div id="MSearchBox" class="MSearchBoxInactive"> | ||
| <span class="left"> | ||
| <img id="MSearchSelect" src="search/mag_sel.png" | ||
| onmouseover="return searchBox.OnSearchSelectShow()" | ||
| onmouseout="return searchBox.OnSearchSelectHide()" | ||
| alt=""/> | ||
| <input type="text" id="MSearchField" value="Search" accesskey="S" | ||
| onfocus="searchBox.OnSearchFieldFocus(true)" | ||
| onblur="searchBox.OnSearchFieldFocus(false)" | ||
| onkeyup="searchBox.OnSearchFieldChange(event)"/> | ||
| </span><span class="right"> | ||
| <a id="MSearchClose" href="javascript:searchBox.CloseResultsWindow()"><img id="MSearchCloseImg" border="0" src="search/close.png" alt=""/></a> | ||
| </span> | ||
| </div> | ||
| </li> | ||
| </ul> | ||
| </div> | ||
| <div id="navrow2" class="tabs2"> | ||
| <ul class="tablist"> | ||
| <li><a href="files.html"><span>File List</span></a></li> | ||
| <li><a href="globals.html"><span>Globals</span></a></li> | ||
| </ul> | ||
| </div> | ||
| </div><!-- top --> | ||
| <div id="side-nav" class="ui-resizable side-nav-resizable"> | ||
| <div id="nav-tree"> | ||
| <div id="nav-tree-contents"> | ||
| <div id="nav-sync" class="sync"></div> | ||
| </div> | ||
| </div> | ||
| <div id="splitbar" style="-moz-user-select:none;" | ||
| class="ui-resizable-handle"> | ||
| </div> | ||
| </div> | ||
| <script type="text/javascript"> | ||
| $(document).ready(function(){initNavTree('_r_e_a_d_m_e_8md.html','');}); | ||
| </script> | ||
| <div id="doc-content"> | ||
| <!-- window showing the filter options --> | ||
| <div id="MSearchSelectWindow" | ||
| onmouseover="return searchBox.OnSearchSelectShow()" | ||
| onmouseout="return searchBox.OnSearchSelectHide()" | ||
| onkeydown="return searchBox.OnSearchSelectKey(event)"> | ||
| </div> | ||
|
|
||
| <!-- iframe showing the search results (closed by default) --> | ||
| <div id="MSearchResultsWindow"> | ||
| <iframe src="javascript:void(0)" frameborder="0" | ||
| name="MSearchResults" id="MSearchResults"> | ||
| </iframe> | ||
| </div> | ||
|
|
||
| <div class="header"> | ||
| <div class="headertitle"> | ||
| <div class="title">README.md</div> </div> | ||
| </div><!--header--> | ||
| <div class="contents"> | ||
| <div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno"> 1</span> Arduino Task Scheduler</div> | ||
| <div class="line"><a name="l00002"></a><span class="lineno"> 2</span> ----------------------</div> | ||
| <div class="line"><a name="l00003"></a><span class="lineno"> 3</span> </div> | ||
| <div class="line"><a name="l00004"></a><span class="lineno"> 4</span> This library implements a simple, preemptive task scheduler that is executed in parallel to the 1ms timer interrupt </div> | ||
| <div class="line"><a name="l00005"></a><span class="lineno"> 5</span> used for the Arduino millis() function. It allows to define cyclic tasks or tasks that should be executed in the future</div> | ||
| <div class="line"><a name="l00006"></a><span class="lineno"> 6</span> in parallel to the normal program execution inside the main loop.</div> | ||
| <div class="line"><a name="l00007"></a><span class="lineno"> 7</span> </div> | ||
| <div class="line"><a name="l00008"></a><span class="lineno"> 8</span> The task scheduler is executed every 1ms. A possibly running task is interrupted by this and only resumed after all succeeding tasks have finished. This means </div> | ||
| <div class="line"><a name="l00009"></a><span class="lineno"> 9</span> that always the task started last has the highest priority. This effect needs to be kept in mind when programming a software using this library.</div> | ||
| <div class="line"><a name="l00010"></a><span class="lineno"> 10</span> </div> | ||
| <div class="line"><a name="l00011"></a><span class="lineno"> 11</span> Notes:</div> | ||
| <div class="line"><a name="l00012"></a><span class="lineno"> 12</span>  - Deadlocks can appear when one task waits for another taks which was started before.</div> | ||
| <div class="line"><a name="l00013"></a><span class="lineno"> 13</span>  - Timing critical tasks may not execute properly when they are interrupted for too long by other tasks. Thus it is recommended to keep task execution as short as possible.</div> | ||
| <div class="line"><a name="l00014"></a><span class="lineno"> 14</span>  - The Arduino MEGA leaves the interrupts state shortly after starting the task scheduler which makes the scheduler reentrant and allows any other interrupt (timer, UART, etc.) to be triggered.</div> | ||
| <div class="line"><a name="l00015"></a><span class="lineno"> 15</span>  - The Arduino DUE enables other interrupts by using the lowest possible priority (15) for the task scheduler interrupt.</div> | ||
| <div class="line"><a name="l00016"></a><span class="lineno"> 16</span> </div> | ||
| <div class="line"><a name="l00017"></a><span class="lineno"> 17</span> Warning: The Arduino Due does not support reeantrant interrupts due to HW limitations. This means that unlike the Arduino MEGA the DUE is not able to execute </div> | ||
| <div class="line"><a name="l00018"></a><span class="lineno"> 18</span> fast 1ms tasks several times before finishing a slower tasks with for example a 10ms timebase. This problem will be especially visible if the sum of the </div> | ||
| <div class="line"><a name="l00019"></a><span class="lineno"> 19</span> execution time of all tasks is greater than the execution period of the fastest task.</div> | ||
| <div class="line"><a name="l00020"></a><span class="lineno"> 20</span> </div> | ||
| <div class="line"><a name="l00021"></a><span class="lineno"> 21</span> Supported Boards:</div> | ||
| <div class="line"><a name="l00022"></a><span class="lineno"> 22</span>  - all boards using the Atmel ATMega328 controller, e.g. Arduino Uno and Nano</div> | ||
| <div class="line"><a name="l00023"></a><span class="lineno"> 23</span>  - all boards using the Atmel ATMega2560 controller, e.g. Arduino Mega</div> | ||
| <div class="line"><a name="l00024"></a><span class="lineno"> 24</span>  - all boards using the Atmel SAM3X8E controller, e.g. Arduino Due</div> | ||
| <div class="line"><a name="l00025"></a><span class="lineno"> 25</span> </div> | ||
| <div class="line"><a name="l00026"></a><span class="lineno"> 26</span> Consumed interrupt:</div> | ||
| <div class="line"><a name="l00027"></a><span class="lineno"> 27</span>  - Atmel ATMega328 & ATMega2560: Scheduler uses TIMER0_COMPA interrupt. This maintains millis() and analogWrite() functionality on T0 pins. However, </div> | ||
| <div class="line"><a name="l00028"></a><span class="lineno"> 28</span>  frequent changes of the duty cycle using analogWrite() lead to a jitter in scheduler timing.</div> | ||
| <div class="line"><a name="l00029"></a><span class="lineno"> 29</span>  - Atmel SAM3X8E: Scheduler uses TC3 interrupt.</div> | ||
| <div class="line"><a name="l00030"></a><span class="lineno"> 30</span> </div> | ||
| <div class="line"><a name="l00031"></a><span class="lineno"> 31</span> CPU runtime:</div> | ||
| <div class="line"><a name="l00032"></a><span class="lineno"> 32</span>  - Atmel ATMega328 & ATMega2560:</div> | ||
| <div class="line"><a name="l00033"></a><span class="lineno"> 33</span>  - 5&mu;s without pending tasks</div> | ||
| <div class="line"><a name="l00034"></a><span class="lineno"> 34</span>  - 12&mu;s + task duration when tasks are executed</div> | ||
| <div class="line"><a name="l00035"></a><span class="lineno"> 35</span>  - Atmel SAM3X8E:</div> | ||
| <div class="line"><a name="l00036"></a><span class="lineno"> 36</span>  - tbd&mu;s without pending tasks</div> | ||
| <div class="line"><a name="l00037"></a><span class="lineno"> 37</span>  - tbd&mu;s + task duration when tasks are executed</div> | ||
| <div class="line"><a name="l00038"></a><span class="lineno"> 38</span> </div> | ||
| <div class="line"><a name="l00039"></a><span class="lineno"> 39</span> Have fun!</div> | ||
| <div class="line"><a name="l00040"></a><span class="lineno"> 40</span> </div> | ||
| <div class="line"><a name="l00041"></a><span class="lineno"> 41</span> ====================================</div> | ||
| <div class="line"><a name="l00042"></a><span class="lineno"> 42</span> </div> | ||
| <div class="line"><a name="l00043"></a><span class="lineno"> 43</span> # Revision History</div> | ||
| <div class="line"><a name="l00044"></a><span class="lineno"> 44</span> </div> | ||
| <div class="line"><a name="l00045"></a><span class="lineno"> 45</span> 1.0 (2019-10-12): </div> | ||
| <div class="line"><a name="l00046"></a><span class="lineno"> 46</span>  - initial release</div> | ||
| </div><!-- fragment --></div><!-- contents --> | ||
| </div><!-- doc-content --> | ||
| <!-- start footer part --> | ||
| <div id="nav-path" class="navpath"><!-- id is needed for treeview function! --> | ||
| <ul> | ||
| <li class="navelem"><b>README.md</b></li> | ||
| <li class="footer">Generated by | ||
| <a href="http://www.doxygen.org/index.html"> | ||
| <img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.8.9.1 </li> | ||
| </ul> | ||
| </div> | ||
| </body> | ||
| </html> |
Oops, something went wrong.